U.S. patent application number 10/865632 was filed with the patent office on 2005-12-15 for printer media transport for variable length media.
Invention is credited to Cook, Brian Dale, Klein, William Scott.
Application Number | 20050275150 10/865632 |
Document ID | / |
Family ID | 35459715 |
Filed Date | 2005-12-15 |
United States Patent
Application |
20050275150 |
Kind Code |
A1 |
Cook, Brian Dale ; et
al. |
December 15, 2005 |
Printer media transport for variable length media
Abstract
Printer (1) has a pivotally mounted autocompensating system (19)
mounted at an intermediate position in paper guide (17). That
system (19) is driven by a motor (40) through a slip drive (70, 72,
74). The motor also drives paper feed system (15). When the motor
turns in a direction to feed by system (15), the intermediate
system is moved away from the paper guide. When a sheet reaches a
position to be fed by the intermediate system, the motor is
reversed, and the intermediate system pivots against the paper for
moving it further through the paper guide.
Inventors: |
Cook, Brian Dale;
(Nicholasville, KY) ; Klein, William Scott;
(Richmond, KY) |
Correspondence
Address: |
LEXMARK INTERNATIONAL, INC.
INTELLECTUAL PROPERTY LAW DEPARTMENT
740 WEST NEW CIRCLE ROAD
BLDG. 082-1
LEXINGTON
KY
40550-0999
US
|
Family ID: |
35459715 |
Appl. No.: |
10/865632 |
Filed: |
June 10, 2004 |
Current U.S.
Class: |
271/109 |
Current CPC
Class: |
B65H 2515/32 20130101;
B65H 2511/51 20130101; B65H 2515/32 20130101; B65H 2403/40
20130101; B65H 3/0676 20130101; B65H 2220/01 20130101; B65H 2220/01
20130101; B65H 2220/02 20130101; B65H 2404/1441 20130101; B41J
13/0018 20130101; B65H 5/06 20130101; B65H 2511/51 20130101; B65H
2511/11 20130101; B65H 7/02 20130101; B65H 2404/16 20130101; B65H
2511/11 20130101 |
Class at
Publication: |
271/109 |
International
Class: |
F16H 061/18; F16H
061/16; B65H 003/06 |
Claims
What is claimed is:
1. An imaging device comprising an imaging station, a sheet media
tray spaced from said imaging station, a media guide path between
said imaging station and said media tray a media drive member to
move sheet media from said sheet media tray into said paper guide
path, a pivotally mounted first autocompensating system located in
said paper guide path for driving media, and a motor to provide
torque to said autocompensating system.
2. The imaging device as in claim 1 in which said first
autocompensating system comprises a slip drive from said motor
operative to move said first autocompensating system away from said
media guide path when said motor is rotating to provide torque to
said first autocompensating system opposite to torque for media
feed in said guide by said first autocompensating system.
3. The imaging device as in claim 2 also comprising a second
pivotally mounted autocompensating system to feed media from said
sheet media guide through said media guide path at least to a
location at which said first autocompensating system can feed said
media.
4. The imaging device as in claim 3 also comprising a
media-presence sensor located to sense media fed in said sheet
media guide to a location to be fed by said first autocompensating
system, said motor also providing torque to said second
autocompensating system.
5. The method performed with the apparatus of claim 4 comprising
the steps of feeding media from said tray through said guide while
operating said motor to provide torque to said first
autocompensating system to move said first autocompensating system
away from said media path, sensing said media presence with said
sensor, and then operating said motor to provide torque to said
first autocompensating system to feed media by said first
autocompensating system.
6. An imaging device comprising an imaging station, a sheet media
tray spaced from said imaging station, a media guide path between
said imaging station and said media tray, a pivotally mounted first
autocompensating system located in said paper guide path for
driving media, a pivotally mounted second autocompensating system
to feed media from said sheet media tray through said media guide
path at least to a location at which said first autocompensating
system can feed said media, and a motor to provide torque to said
first autocompensating system and said second autocompensating
system.
7. The imaging device as in claim 6 in which said first
autocompensating system comprises a slip drive from said motor
operative to move said first autocompensating system away from said
media guide path when said motor is rotating to provide torque to
said first autocompensating system opposite to torque for media
feed in said guide by said first autocompensating system.
8. The imaging device as in claim 4 also comprising a
media-presence sensor located to sense media fed in said sheet
media guide to a location to be fed by said first autocompensating
system.
9. The method performed with the apparatus of claim 7 comprising
the steps of feeding media from said tray through said guide while
operating said motor to provide torque to said first
autocompensating system to move said first autocompensating system
away from said media path, sensing said media presence with said
sensor, and then operating said motor to provide torque to said
first autocompensating system to feed media by said first
autocompensating system.
Description
TECHNICAL FIELD
[0001] This invention relates to imaging devices that feed variable
length media over a paper path longer than the length of some of
the media to be fed.
BACKGROUND OF THE INVENTION
[0002] Printing devices utilizing a media tray under the device
typically feed the media out of the tray to the rear and around a
"C" shaped path to enter the imaging area and exit to the front of
the device. This provides a very compact machine. Because of the
varying lengths of media fed through such a device, some mechanism
must be provided to accommodate the discrepancy between the length
of short media and the path length. This conventionally is done by
using a relatively large drive roller (or rollers) which move the
media toward non-driven idler rollers to maintain contact with the
media while it is being fed around the path and into the imaging
area.
DISCLOSURE OF THE INVENTION
[0003] This invention employs in an intermediate location in the
feed path a drive system which has been used successfully as the
initial media pick-and-feed system from the tray. That mechanism is
an autocompensting system, comprising one or more feed rollers on a
swing arm pivoted around a gear train which drives the feed roller.
Autocompensating systems are cost-effective and may be moved toward
the media for feeding and off the media by reversing the torque to
the gear train. An autocompensating system is also used to pick
paper from the tray, and both autocompensating systems may be
driven from one motor through different drive trains.
[0004] The intermediate autocompensating system is moved away from
the feed path until media is driven past that system. Then that
system is applied to move the media while the tray autocompensating
system is not driven.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The details of this invention will be described in
connection with the accompanying drawings, in which
[0006] FIG. 1 is a printer and is illustrative of a long, C-shaped
path between a paper tray and the imaging printhead,
[0007] FIG. 2 is a partial, somewhat more detailed, perspective
view downward on the tray and the front guide.
[0008] FIG. 3 is a view from the same side as the view of FIG. 2 of
the motor and gear train to the autocompensating systems,
[0009] FIG. 4 is a view from the side opposite the view of FIG. 2
of motor and gear trains to the autocompensating systems.
[0010] FIG. 5 illustrates the autocompensating systems in some
detail and the drive path between tray and nip roller preceding the
imaging station.
[0011] FIG. 6 is a perspective view of selected elements to explain
the slip drive, and
[0012] FIG. 7 is a perspective view of selected elements from the
side opposite to that of FIG. 6 to explain the slip drive.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] FIG. 1 is illustrative of a printer 1 with specific elements
pertinent to this invention. Printer 1 may be a standard inkjet
printer in most respects. As such it has a bottle printhead 3 which
jets dots of ink through nozzles not shown, which are located above
a sheet 5 of paper or other media at a imaging station 7
[0014] Imaging station 7 is located past nip rollers 9a, 9b which
grasp paper 5 in the nip of rollers 9a, 9b and move it under
printhead 3. Nip rollers 9a, 9b are stopped normally several times
to permit printhead 3 to partially image sheet 5 by moving across
sheet 5 (in and out of the view of FIG. 1) while expelling dots in
the desired pattern. In a draft mode the number of such
intermittent stops may be only two, while in a quality mode that
number may be five or more.
[0015] Nip rollers 9a, 9b push paper through the imaging station 7
where they enter exits rollers 11a, 11b, 11c, and 11d. Although
rollers are by far the most common mechanism to transport the
imaged sheet 5 out of the printer 1 to the user of the printer 1,
virtually any grasping device can be used, such as a belt and
pressing device or pneumatic suction device.
[0016] The printer of FIG. 1 has a paper tray 13 located on the
bottom. Tray 13 constitutes a bin in which a stack of paper or
other media sheets 5 are held to be imaged. Having tray 13 located
on the bottom of printer 1 permits a large stack of sheets 5 to be
in the printer 1. This spaces the tray 13 from the print stations
7, the distance from pick roller 15a of tray 13 to nip rollers 9a,
9b being longer than the length of some media sheets 5 to be
printed. Pick roller 15a is a part of an autocompensating swing
mounted system 15.
[0017] A C-shaped paper guide 17 is made up of rear guide surface
17a and spaced, generally parallel, front guide surface 17b. Both
surfaces have spaced ridges (shown for surface 17b as 17bb in FIG.
2), as is common. Guide 17 directs a sheet 5 to nip rollers 9a, 9b.
Intermediate in guide 17 is drive roller 19a, which is a part of an
autocompensating swing-mounted system 19. Sensor arm 21 is moved by
a sheet 5 to detect the sheet 5 at system 19.
[0018] Pick roller 15a at tray 13 and drive roller 19a combine to
move sheets 5 from tray 13 to nip rollers 9a, 9b. Drive roller 19a
is effective to move short media into rollers 9a, 9b, when pick
roller 15a is no longer in contact with the sheet 5.
[0019] Operational control is by electronic data processing
apparatus, shown as element C in FIG. 1. Such control is now
entirely standard. A standard microprocessor may be employed,
although an Application Specific Integrated Circuit (commonly known
as an ASIC) is also employed, which is essentially a special
purpose computer, the purpose being to control all actions and
timing of printer 1. Electronic control is so efficient and
versatile that mechanical control by cams and relays and the like
is virtually unknown in imaging. However, such control is not
inconsistent with this invention.
[0020] Movement of parts in the printer shown in FIGS. 2, 3 and 4
is by one motor. With respect to FIG. 3 motor 30 is seen to drive a
large gear 32 through a belt 34. Gear 32 has integral with it a
central, smaller gear 32a. The gear 32 is meshed with large gear
36, which is integral with shaft 38 to provide torque to
autocompensating system 15.
[0021] Similarly, gear 32a meshes with idler gear 40 which meshes
with a somewhat larger gear 42. Gear 42 has integral with it a
central, smaller gear 42a (best seen in FIG. 4). Gear 42a is meshed
with gear 44, which is integral with splined shaft 46 to provide
torque to autocompensating system 19
[0022] As is evident from the gears trains, rotation of motor 30
counterclockwise as viewed in FIG. 3 applies a downward torque (as
discussed below) to autocompensating system 15 and an upward torque
(as discussed below) to autocompensating system 19. Rotation of
motor 30 clockwise reversed the direction of torque to both system
15 and system 19.
[0023] FIGS. 3 and 4 also illustrate a roller 48, which is mounted
to roll free, which drive roller 19a contacts when driving should
no media sheet 5 be under roller 19a, which avoids a high downward
torque being generated. With respect to roller 15a in the tray 13,
no comparable apparatus to roller 48 is used as the high torque can
be used to signal absence of paper and therefore to terminate drive
to autocompensating system 15.
[0024] The autocompensating systems 15 and 19 of this embodiment
are not novel with respect to their design and function A slip
drive closely similar to that employed has been sold in a prior art
device of the assignee of this invention. However, that was
employed to lift the paper feed autocompensation system off the
paper stack after the top sheet is fed a predetermined distance.
This invention employs the slip drive with the autocompensating
system located in the paper guide 17.
[0025] With reference to FIG. 5, autocompensating system 15 is seen
to have four meshed gears 50, 52, 54 and 56 each meshed to the next
gear in a linear train and supported within a bracket 58. Gear 56
is integral with drive roller 15a so that it moves both by pivoting
(when gear 56 pivots) and by rotation (when gear 56 rotates). Gear
50 on the opposite end of the train of gears 50, 53, 54, and 56 is
rotated by shaft 38 (FIGS. 2, 3 and 4). Similarly for
autocompensating system 19 gears 60, 62, 64 and 66 are each meshed
to the next gear in a linear train and supported within a bracket
68. Gear 66 is integral with drive roller 19a so that it moves both
by pivoting (when gear 66 pivots) and by rotation (when gear 66
rotates).
[0026] Assuming counterclockwise torque to gear 50 and clockwise
torque to gear 60, so long as gear 56 of system 15 or gear 66 of
system 19 is not rotating, the torque pivots bracket 58 or bracket
68 respectively and the force against a sheet 5 of drive roller 15a
and 19a increases toward the maximum pivoting force which can be
applied by motor 30. This force is immediately relieved when gear
56 rotates in the case of system 15 and when gear 66 rotated in the
case of system 19. Such rotation occurs when a sheet 5 is being
moved, and it is the increase in pivot force against the sheet
until it is moved which constitutes autocompensating in the
systems.
[0027] Opposite or no rotation from the feeding rotation of gears
50 and 60 relieve pivoting torque because the direction of pivot is
away from the feeding position and therefore the gears 56 and 66
respectively are free to rotate. To prevent such rotation with
respect to system 15, gear 50 is driven through a one-way clutch,
(not shown), which may be a conventional
ball-and-unsymmetrical-notch clutch or other clutch.
[0028] FIG. 5 shows autocompensation system positively moved away
from the guide 17. This occurs when gear 60 is driven in the
direction opposite to sheet feed. To achieve that, an added
mechanism is applied to the autocompensation system 15, which is
illustrated in FIG. 6 and FIG. 7.
[0029] This mechanism is a slip drive. As shown in FIG. 6, within
the housing 70 of autocompensating system 19 is a coil spring 72
mounted on drive shaft 46 and having one side in contact with the
face of gear 66.
[0030] As shown in FIG. 7, housing 70 has a cylindrical well 74
with bottom face 76 which receives the side of spring 72 (FIG. 6)
opposite to that which faces gear 66. The dimensions of well 74 are
such that spring 72 is compressed.
[0031] With spring 72 compressed, the turning of gear 66 turns
spring 72 and the turning of spring 72 tends to rotate the entire
housing 70, since well 74 is integral with housing 70. However,
when further rotation is blocked, spring 72 simply slips.
[0032] When gear 66 is rotated in the reverse feeding direction,
system 19 is moved away from the drive path of guide 17 as shown in
FIG. 5, where it is stopped by being blocked by a fixed member 80,
which may be integral with the structure forming guide 17.
[0033] When gear 66 is rotated in the feeding direction, spring 72
adds somewhat to the downward force while slipping.
[0034] In operation, under control of controller C, motor 30 is
driven to feed a sheet 5 from tray 13 by rotating autocompensating
system 15 downward. Autocompensating system 19 is necessarily
driven by the slip drive to move away from the paper feed
direction. Accordingly, when a sheet 5 is being moved by system 15,
system 19 is moved completely out of guide path 17, as shown in
FIG. 4.
[0035] In normal operation, the sheet 5 moves to encounter sensor
arm 21 (FIG. 1). Then the controller C reverses motor 30. The
direction of rotation of motor 30 is reversed, causing
autocompensating system 19 to pivots to contact sheet 5, while
autocompensating system 15 has no torque since the one-way clutch 9
(not shown), prevents any drive to autocompensating system 15.
[0036] System 19 moves sheets 5 until they reach nip roller 9a, 9b
and, preferably, become somewhat buckled. The buckling serves to
align sheets 5. The remaining imaging operation may be entirely
standard.
[0037] It will be recognized that this invention can take many
mechanical forms, so long as an autocompensating system is used at
least at the intermediate drive location.
* * * * *